Reproachful remark (3-3)
I believe the answer is:
tut-tut
'reproachful remark' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tut-tut that I've seen before include "Noise of disapproval" , "Expression of irritation" , "Repetitive sound of mild disapproval" , "Sounds of disapproval" , "Expression of disapproval - a repetitive palindrome" .)